package com.example.lib;

public class DoubleCheck {
    private static volatile DoubleCheck instance;
    private DoubleCheck(){}
    public  static DoubleCheck getInstance(){
        if (instance==null){
            synchronized (DoubleCheck.class){
                if (instance==null){
                    instance=new DoubleCheck();
                }
            }
        }
        return instance;
    }
}
